Draining the sump of an ice maker to prevent growth of harmful biological material

Abstract

An ice maker having a refrigeration system, a water system and a control system. The refrigeration system includes an ice formation device. The water system supplies water to the ice formation device, and includes a water reservoir (e.g., a sump or float chamber) for holding water to be formed into ice and a discharge valve in fluid communication with the water reservoir. The control system includes an ice level sensor adapted to sense the ice level in an ice storage bin, and a controller adapted to cause water to drain from the water reservoir when the ice storage bin is full. Substantially or all of the water remaining in the water reservoir is drained such that while the ice maker is not making ice the water reservoir is empty of water.

What is claimed: 
     
       1. An ice maker for forming ice, the ice maker comprising:
 (i) a refrigeration system comprising a compressor and an ice formation device; 
 (ii) a water system for supplying water to the ice formation device, the water system comprising a water pump and a water reservoir adapted to hold water to be formed into ice and a discharge valve in fluid communication with the water reservoir; 
 (iii) an ice storage bin for storing the formed ice; and 
 (iv) a control system comprising an ice level sensor adapted to sense whether the ice storage bin is full of ice, a water level sensor adapted to sense a water level in the water reservoir, and a controller adapted to
 cause the discharge valve to open and to cause the water pump to pump water out of the water reservoir through the discharge valve to allow water to drain from the water reservoir based upon an indication from the ice level sensor that the ice storage bin is full of ice, 
 cause the discharge valve to close and to stop the water pump based on an indication from the water level sensor that the water reservoir is empty; 
 
 wherein the water level sensor includes a pressure sensor and a fitting; 
 wherein the fitting comprises a base portion and a tapered portion that tapers as it extends upward from the base portion toward a top of the fitting; and 
 wherein the tapered portion includes a bottom tapered portion and a top tapered portion and the bottom tapered portion is more tapered than the top tapered portion. 
 
     
     
       2. The ice maker of  claim 1 , wherein the ice formation device comprises:
 an ice making chamber; and 
 an auger within the ice making chamber for removing ice formed in the ice making chamber. 
 
     
     
       3. The ice maker of  claim 1 , wherein the ice formation device comprises an evaporator and a freeze plate thermally coupled to the evaporator. 
     
     
       4. A method of controlling an ice maker, the ice maker comprising (i) a refrigeration system comprising a compressor and an ice formation device, (ii) a water system for supplying water to the ice formation device, the water system comprising a water reservoir adapted to hold water to be formed into ice and a discharge valve in fluid communication with the water reservoir, (iii) an ice storage bin for storing the formed ice; and (iv) a control system comprising an ice level sensor adapted to sense whether the ice storage bin is full of ice, a water level sensor adapted to sense a water level in the water reservoir, and a controller adapted to control the operation of the refrigeration system and the water system, the method comprising:
 receiving, by the controller, an indication from the ice level sensor that the ice storage bin is full of ice; 
 causing, by the controller, the compressor to turn off; 
 causing, by the controller, the discharge valve to open to drain water from the water reservoir; 
 receiving, by the controller, an indication from the water level sensor that the water reservoir is empty; and 
 causing, by the controller, the discharge valve to close and based on the indication from the water level sensor that the water reservoir is empty; 
 wherein the water level sensor includes a pressure sensor and a fitting; 
 wherein the fitting comprises a base portion and a tapered portion that tapers as it extends upward from the base portion toward a top of the fitting; and 
 wherein the tapered portion includes a bottom tapered portion and a top tapered portion and the bottom tapered portion is more tapered than the top tapered portion. 
 
     
     
       5. The method of  claim 4 , further comprising:
 causing, by the controller, a water pump to turn on to pump water from the water reservoir through the discharge valve. 
 
     
     
       6. The method of  claim 4 , further comprising the steps of:
 receiving, by the controller, an indication from the ice level sensor that the ice storage bin is not full of ice; and 
 causing, by the controller, the compressor to turn on. 
 
     
     
       7. The method of  claim 4 , wherein the ice formation device comprises an ice making chamber, and wherein the step of opening the discharge valve causes water to drain from the ice making chamber.